The present invention relates to ladder standoff devices adapted to be attached to a ladder to support the ladder at various spacings from and orientations to an adjacent wall structure and which, more particularly, can be readily attached to and detached from the ladder by a worker standing on the ladder, and readily manipulated between operative and deactivated positions by such a person standing on the ladder.
A variety of ladder standoff devices have been suggested heretofore. Some of these prior devices have taken the form of tubular members which are secured to the rails or rungs of the ladder, e.g., as in Grenier U.S. Pat. No. 4,184,569 and Spencer U.S. Pat. No. 4,061,203, to permit a ladder to be supported adjacent a wall in spaced relation to the wall. Other standoff devices have been suggested wherein the ladder attachment includes one or more wheels along with a mounting and adjusting arrangement for varying the position of the wheels relative to the ladder and an adjacent wall surface; see in this respect Larson U.S. Pat. No. 4,143,743, DelPrete U.S. Pat. No. 3,773,143, O'Dell U.S. Pat. No. 3,713,510, Sunshine U.S. Pat. No. 3,100,026, Niedojadlo U.S. Pat. No. 2,797,037, Pals U.S. Pat. No. 2,788,930, Roketa U.S. Pat. No. 2,597,902, Otterson U.S. Pat. No. 2,503,351, Owen U.S. Pat. No. 2,272,642, Hollister U.S. Pat. No. 1,825,590, Bauer U.S. Pat. No. 1,600,572, and Lehmann U.S. Pat. No. 1,004,284.
The foregoing prior art devices, all of which are structurally different from the standoff device of the present invention, suffer from the common disadvantage that they are fastened to a ladder in a semi-permanent configuration by means of bolts, nuts, clamps or the like. Such arrangements have severe practical limitations inasmuch as it takes a significant time to attach the device to, or detach it from, a ladder whereby, in some circumstances, a worker may forego the use of the device rather than take the time to install it in its intended fashion; and the attachment means themselves tend to be somewhat unsafe since, after period of use, the threads on the bolts, nuts, etc. which are used for attachment purposes may become stripped, or the bolts, etc., may in themselves be lost. Moreover, these prior devices have had limited utility since, as a practical matter, they must customarily be attached to the uppermost part of a ladder to provide any useful clearance between the ladder and a wall and, when so attached, often get in the way of a worker standing on the ladder. Further, the prior art units are ordinarily not adjustable from a wall sufficiently far to permit a worker standing on the ladder to reach wide overhangs and face boards.
A further major disadvantage of the prior art devices is that, typically, they could not be attached to or detached from a ladder while the worker is actually standing on the ladder; and, in addition, the prior devices were so complex and costly that they were considered to have limited, at most, practical use by people working in the trades.
The present invention is intended to obviate all of these disadvantages. The improved ladder standoff unit of the present invention is far simpler in construction than ladder standoff devices suggested heretofore, is arranged so that it can be readily attached to or detached from a ladder while a worker is actually standing on the ladder at an elevated position, and adjusted in a variety of dimensions and orientations while the worker is on the ladder, to permit the worker to reach wide overhangs, faceboards, walls, window openings, etc., without the ladder or the standoff unit getting in the way of the operator of the device. Moreover, the standoff device of the present invention eliminates the need for nuts, bolts, clamps, etc., for attachment of the device to the ladder, and is characterized by attachment arrangements that permanently form a portion of the standoff device itself, and which may be readily manipulated for attachment and detachment purposes, thereby eliminating the possible loss of parts and the resultant difficulties which have characterized prior art units.